diff --git a/app/api.rb b/app/api.rb
index 8a98b0e5..2dbba20f 100644
--- a/app/api.rb
+++ b/app/api.rb
@@ -123,7 +123,7 @@ post '/api/upload' do
     end
 
     if SiteFile.name_too_long? file[:filename]
-      api_error 400, 'file_name_too_long', "#{file[:filename]} filename is too long"
+      api_error 400, 'file_name_too_long', "#{file[:filename]} filename is too long (exceeds 255 characters)"
     end
   end
 
diff --git a/models/site_file.rb b/models/site_file.rb
index afef3139..7420dcd5 100644
--- a/models/site_file.rb
+++ b/models/site_file.rb
@@ -6,7 +6,7 @@ class SiteFile < Sequel::Model
   CLASSIFIER_LIMIT = 1_000_000
   CLASSIFIER_WORD_LIMIT = 25
   FILE_PATH_CHARACTER_LIMIT = 1200
-  FILE_NAME_CHARACTER_LIMIT = 100
+  FILE_NAME_CHARACTER_LIMIT = 255
   unrestrict_primary_key
   plugin :update_primary_key
   many_to_one :site